The immediate aim of this project is to develop techniques for the effective assembly storage, analysis, and dissemination of molecular structural data on drugs and hormones. Formats for data handling and presentation will be designed to foster easy assimilation and utilization of this information by endocrinologists, medicinal chemists, biophysicists, and pharmacologists interested in the molecular level action of biomedically active molecules. A two volume Atlas of Steroid Structure, which presents exact structural details for approximately 200 steroidal compounds is in preparation. The 472 data pages of the first volume (published October 1975) include an exhaustive tabulation of molecular geometry and over 1000 ink drawings illustrating the most significant intramolecular and intermolecular structural features of 118 estranes, androstanes, and pregnanes including many of the most active steroid hormones. This Atlas will facilitate comparative studies of steroid molecular structures and the understanding of structural-functional relationships. The second volume of the Atlas of Steroid Structure and a similar volume concerned with the conformational analysis of thyroactive hormones, analogues and precursors, are also in preparation. All structural data of these and other classes of bioactive molecules are being placed in the PROPHET system, a national computer network of the NIH Division of Research Resources, designed to aid in the correlation of structure with function in pharmacological and toxicological studies. Software will be developed in the PROPHET system to allow users with varied interests to tap the wealth of information contained in the structural data and to foster productive interdisciplinary collaborations in functional analysis.